The invention relates to creating productive uses, e.g., detection systems or compound manufacturing, associated with formation or nucleation and growth of hair-like protrusive metal structures that have been observed to form from a variety of metals and/or alloys. These hair-like or protrusive metal structures are sometimes described as whiskers. Whiskers are normally viewed as undesirable emergent structures associated with use of a variety of compounds in electronic device manufacturing such as tin. The cause of whisker formation has been hypothesized but not clearly proven thus there is a substantial degree of uncertainty associated with whisker formation. A large number of defects are associated with whisker formation. Attempts to eliminate whisker formation have largely failed including creation of manufacturing processes where lead use is avoided. Widespread experimentation and research have failed to provide needed results or countermeasures to risks associated with whisker formation.
Disclosed embodiments of the invention include a variety of apparatuses and methods associated with forming and using whiskers as well as forming whisker compounds. For example, whisker detection modules can be created which provide a whisker surveillance capability. Exemplary whisker detection modules can further be coupled with a whisker response system such as an alarm or whisker response system such as activation of a moveable dispenser applying insulating or whisker negating reactive material on a whisker being formed. Another aspect of the invention includes providing a variety of environments or microenvironments with regard to a whisker forming structure to affect whisker creation such as mirroring an environment associated with a part under whisker surveillance or maximizing whisker formation. Another example includes provision of a variety of embodiments for manufacturing compounds of whiskers of various metal and metal alloys, including structures and methods is provided. Whisker compounds produced using various embodiments of the invention can be used for various applications.
For example, one aspect of the invention includes a method to manufacture different types of compounds of whiskers generated from the electroplated surfaces/substrates of metals and the alloys of the metals, such as Tin (Sn) and many other low melting metals such as Zinc (Zn), Silver (Ag), Gold (Au), Cadmium (Cd), Aluminum (Al), Lead (Pb), Indium (In), in diameters scales ranging from nm to mm and in lengths up to 10 mm or more. Formation and occurrence of these metal whiskers protruding out of soldered areas of microelectronic devices are nuisance to electronic circuits which cause short circuit failures, but their compounds such as SnO2, ZnO, etc, in various forms and generated from non-electroplated substrates have been researched and employed in various applications such as gas sensors or anodes for lithium ion batteries, etc. These nano (nm)/micro (μm) sized needle shaped compounds are made by various non-electroplating techniques. These various techniques do not use the needle shaped whiskers generated from electroplating process to intentionally produce chemical compounds such as oxides, nitrides, carbides, sulphides, hydrides, or any complex compounds thereof such as carbonitrides, or sulphates etc. by generating the metal or metal alloy whisker and subsequently reacting them in various environment such as Carbon, (C), Nitrogen (N), Sulfur (S), Oxygen (O), Hydrogen (H) or their combinations to generate whisker compounds. Considering above the present innovation specifically focuses at intentionally creating whiskers of various metals such as Tin (Sn), Zinc (Zn), Silver (Ag), Gold (Au), Cadmium (Cd), Aluminum (Al), Lead (Pb), Indium (In) and alloys of the metals, and chemically reacting the generated whiskers in various gaseous or liquidous environments with various elements such as O, C, S, N, H or their combinations, with the objective to form their whisker compounds such as SnO2, ZnO etc. or generating any organometallic compounds of the whiskers. The above said whisker compounds can be used for any suitable application such as gas sensors for SnO2 or anodes for lithium ion batteries such as SnO2, or ZnO whiskers as battery components. Thus any application that uses the whisker compounds produced by the above mentioned manufacturing procedure involving generation of whiskers from an electroplating process and subsequent/simultaneous chemical reaction of the whiskers with an exposed environment will be encompassed by aspects of exemplary embodiments of this innovation. The exemplary process stated above in this innovation does not bound the whisker compound by extent of the chemical reaction of the electroplating produced whisker with the exposed environment, or size and shape of the original pure metal or metal alloy whisker, and the whisker compound generated.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived.